1. Field of the Invention
The present invention relates to an Internet Protocol (IP) phone terminal that has a relay function between a network and an external terminal such as a personal computer (PC), a server for registering address information of a user of the IP phone terminal, an authentication apparatus that authenticates the user of the IP phone terminal, a communication system incorporating the above apparatuses, a communication method for the above apparatuses, and a computer-readable recording medium that stores therein a computer program for the IP phone terminal.
2. Description of the Related Art
A network-access authentication protocol, such as the IEEE 802.1X, is known as a protocol for permitting a network access only to a terminal authenticated to a certain network system.
In an authentication through the IEEE 802.1X (hereinafter, “802.1X authentication”), an authentication and a connection permission are made at a port level on a connected device. Usually, the 802.1X authentication is performed between an infrastructure switch and a device directly connected to the infrastructure switch.
In a technology disclosed in JP-A 2006-352468 (KOKAI), an authentication by the 802.1X authentication for any one of a plurality of terminals connected to an IEEE 802.1X-compliant port via a switch or the like permits a connection to all the terminals.
In a technology disclosed in JP-A 2006-67057 (KOKAI), when a plurality of terminals is connected to an IEEE 802.1X-compliant port via a switch or the like, the 802.1X authentication and a connection permission are performed on each of the terminals based on a media access control (MAC) address of each of the terminals.
In a technology disclosed in JP-A 2007-206851 (KOKAI), a single sign-on to each terminal is realized by managing in advance information on a correspondence between an IP phone terminal and a thin client terminal.
Recently, an IP phone system has been widely known, which implements a telephone network on an IP network by using a signaling protocol for controlling and relaying a communication between communications devices, such as the session initiation protocol (SIP). An IP phone terminal used in the IP phone system is cabled through the Ethernet (Registered Trademark), and implements a telephone function by performing a call control and a media transfer according to the SIP on the IP network.
When using an IP phone terminal, the user needs to register an SIP address of the user to the IP phone terminal. The registration of SIP address is a processing of associating the SIP address of the user with the SIP address of the IP phone terminal. The user inputs an authentication ID, a password, and the like, to the IP phone terminal in the registration processing. The registration processing is needed for receiving an incoming call addressed to the user correctly, identifying a caller correctly, and setting advanced features, such as a so-called speed dial, of the IP phone terminal for each user. In some cases, for a convenience of the user, the setting is made to allow receiving an incoming call and making an outgoing call by assuming that an SIP address is registered by a default user even without an input of the authentication ID and the password.
Many of IP phone terminals for office use have a built-in switch including an uplink and a downlink one for each to simplify a cabling around a desk. The uplink of the IP phone terminal is connected to a port of an infrastructure switch, and the downlink of the IP phone terminal is connected to a personal computer (PC). With this type of connection, it is possible to use an IP phone terminal and a PC through a single port of the infrastructure switch assigned to the desk.
Generally, this type of connection is configured such that a virtual local area network (VLAN) for accommodating the PC is switched in accordance with an authentication result of the 802.1X authentication. In this case, for example, the PC is an 802.1X supplicant, the built-in switch of the IP phone terminal is an 802.1X authenticator, and an authentication server connected to the infrastructure network is an 802.1X authentication server. The 802.1X authentication to the PC is executed among the authentication server, the IP phone terminal, and the PC. When the PC is authenticated by the authentication server, the IP phone terminal determines a VLAN for connecting the PC by referring to information on the VLAN notified by the authentication server, and changes a VLAN setting of a corresponding port.
However, under an environment in which the PC is connected to the infrastructure network via the IP phone terminal as described above, it is necessary to perform the registration processing of the SIP address on the IP phone terminal and the authentication processing on the PC, which causes a cumbersome operation for using the PC.
In other words, to start using the IP phone terminal and the PC at the desk on which the IP phone terminal is installed, the user needs to perform a connection of the PC to the downlink of the IP phone terminal, an operation of the IP phone terminal to register the SIP address of the user to the IP phone terminal, and an operation for the 802.1X authentication to the infrastructure network from the connected PC and receiving a connection permission and a VLAN allocation.